The complex interplay between COVID-19 and economic activity

We introduce a dynamical system to model the complex interaction between COVID-19 and economic activity. The model introduces some novelties not accounted by SIR-like models. The equilibrium of the system is an unstable focus, with fluctuations having increasing size and periodicity. Numerical simulations of the model produce waves which reproduce the pandemic dynamics. In observing the stylized facts linking economics and pandemic and stating related reasonable assumptions, we obtain a Lotka-Volterra co-dynamics. This outcome is confirmed by extensive simulations. The outcomes obtained qualitatively replicate some important stylized facts deepening the knowledge about the role of some parameters in their origin and eventually in their shaping.

Autonomous demand, multiple equilibria and unemployment dynamics

The paper presents a medium-run growth model driven by autonomous demand, where aggregate demand and supply interact and unemployment is present and plays different roles. In particular, it generates a feedback from supply to aggregate demand rooted in the presence of heterogeneous consumers and an uncertain environment. Two are the main consequences of this approach. The first is that multiple equilibria can be generated. The second is that equilibria may have different stability properties. In this perspective, growth becomes a dynamic process where initial conditions matter and history plays an important role.

Local and global analysis of a speculative housing market with production lag

We extend the model of Dieci and Westerhoff [J. Evol. Econ. 22(2), 303-329 (2012)], where the authors analyse a speculative housing market populated by heterogeneous interacting agents described by a two dimensional nonlinear discrete time dynamical system. They show the emergence of complicated dynamics through the occurrence of bifurcations for particular parameter combinations. We enlarge their model in several ways. On one hand, we introduce time lag in the supply side and we consider two new scenarios characterised by agents' expectations formation. First, naive expectations instead of perfect foresight are considered, while in the second scenario, we study a mix between the model of Dieci and Westerhoff [J. Evol. Econ. 22(2), 303-329 (2012)] and the one we propose. As a consequence, we, analytically and numerically, explain the appearance of instability in the housing market providing conditions on the parameters that lead to a bifurcation. On the other hand, thanks to further numerical simulations, we conduct a global analysis providing the structure of the basin of attractions of the map showing coexistence of attractors.

Isolated muscular sarcoidosis mimicking a tumoral lesion

We report a case of a woman with a palpable painful nodule on her left leg. MR and CT showed a lesion that could be described as a neoplasm. Excisonal biopsy revealed a noncaseating granuloma. The woman presented the nodular type of muscular isolated sarcoidosis. Further the disease involved the lungs; this confirmed the accurate diagnosis of sarcoidosis. Sarcoidosis is a chronic, multisystem granulomatous disease of unknown etiology. Muscle involvement is frequent, but often asymptomatic. There are three forms of muscular sarcoidosis: only the nodular type can be recognized by technical imaging. MR and ultrasound are the best methods to attempt the diagnosis of nodular muscular sarcoidosis; nevertheless, the lesion must have a standardized behaviour because it can mimic a malignant neoform. In this case, biopsy is the only tool to identify the disease.

Snap-back repellers and chaotic attractors

When homoclinic orbits to an expanding periodic point exist, the point is called a snap-back repeller. Here, we consider the two-dimensional piecewise-linear map in canonical form, continuous and discontinuous, showing how snap-back repellers may be associated with robust chaotic attracting sets (not only with chaotic repellers). Examples are given both for the continuous and discontinuous maps.

A phase I study of gemcitabine and epirubicin for the treatment of platinum-resistant or refractory advanced ovarian cancer

BACKGROUND

Gemcitabine is active in patients with otherwise resistant or refractory ovarian cancer. As the drug is well tolerated, studies using gemcitabine combined with other antineoplastic agents are needed. The aim of the study was to determine the maximum tolerated dose (MTD) of epirubicin combined with gemcitabine, with and without support of G-CSF.

PATIENTS AND METHODS

Patients with platinum-resistant or refractory ovarian cancer were eligible. Gemcitabine (G) (starting dose 800 mg/m2 day 1 and 8; 200 mg/m2 escalation per level) and epirubicin (E) (starting dose 60 mg/m2 day 1; 15 mg/m2 escalation per level) were given every 21 days for four to six cycles. G-CSF (filgrastim 5 microg/kg/die) was given in case of grade 4 neutropenia (levels without support) or from day 9 up to leukocyte count > 10.000/mm3 after nadir (levels with support). Cohorts of three patients were enrolled at each level, and another three patients were planned, if one dose-limiting toxicity (DLT) was registered. MTD was determined first without and then with G-CSF.

RESULTS

Four levels were studied (G 800 + E 60; G 1000 + E 60; G 1000 + E 75; G 1000 + E 75 + G-CSF) with four, four, three and three patients enrolled, respectively. DLT (grade 4 febrile neutropenia) was observed in two patients at level 3. Thus, G1000 + E 60 mg/m2 was the MTD without G-CSF. The addition of prophylactic G-CSF did not allow a further increase of the dose and grade 4 thrombocytopenia was the DLT at level 4. Non-hematological toxicity was mild. Grade 2 mucositis was reported in four patients. Among the 13 patients with measurable or evaluable disease, 3 partial responses were observed for an overall response rate of 23.1%.

CONCLUSIONS

The combination of gemcitabine 1000 mg/m2 (day 1, 8) and epirubicin at 60 mg/m2 (day 1) is a feasible therapy. Grade 4 neutropenia is frequent and G-CSF support is often required. With prophylactic support of G-CSF, the DLT is thrombocytopenia.

Phase I study with weekly cisplatin-paclitaxel and concurrent radiotherapy in patients with carcinoma of the cervix uteri

BACKGROUND

Cisplatin and paclitaxel are active in cervical cancer and both are able to potentiate the effects of radiotherapy. In this study we evaluated the maximum-tolerated dose (MTD) of paclitaxel in combination with a fixed dose of cisplatin when given weekly concurrently with pelvic radiotherapy to patients with carcinoma of the cervix uteri.

PATIENTS AND METHODS

Eighteen patients with cervical cancer were enrolled in this study. Cisplatin (30 mg/m2) and paclitaxel (starting dose 40 mg/m2; 5 mg/m2 escalation per level) were given on day 1 of radiotherapy and then weekly for six times. Radiotherapy was given to the pelvis with a four-field box technique for five days each week. Patients received 65 Gy in 1.8 Gy fractions. Cohorts of three patients were enrolled at each level and three further patients were included if one or two dose-limiting severe adverse events (SAE) were recorded. SAE was defined as grade 3 or 4 nonhematologic toxicity, excluding nausea or vomiting and alopecia, grade 4 neutropenia or thrombocytopenia, and prolonged (> 1 week) neutropenia or thrombocytopenia.

RESULTS

Four levels were studied (paclitaxel 40, 45, 50, 55 mg/m2) with three, five, four and six patients enrolled, respectively. The MTD of paclitaxel was found at 50 mg/m2/wk and cisplatin 30 mg/m2/wk. Diarrhea was the dose-limiting toxicity. Thirteen patients were evaluable for response: seven complete and five partial responses were obtained with an overall response rate of 92.3%.

CONCLUSIONS

The MTD of paclitaxel is 50 mg/m2/wk when associated to cisplatin 30 mg/m2/wk and concurrent pelvic radiotherapy. Diarrhea is the dose limiting side effect. Preliminary data suggest that concurrent chemoradiotherapy with paclitaxel and cisplatin could be a very active treatment for patients with locally advanced carcinoma of the cervix.

[Importance of endocervical cells in the diagnosis of CIN]

BACKGROUND AND AIM

The authors performed a comparative study to define the role played by the presence of endocervical cells on the smear in the correct diagnosis of CIN.

METHODS

The study was performed from January to December 1996 at the Clinic of Obstetrics and Gynecology of the Second University of Naples and involved 67 women with a histological diagnosis of CIN made in the two previous months of the study. The smears taken earlier were re-examined to assess the endocervical component regarding columnar and metaplastic cells and a comparison was made between smears which were CIN-positive and negative.

RESULTS

The difference between positive and negative CIN smears was statistically non-significant for columnar cells (66% vs 56%), unlike the findings for metaplastic cells (82% vs 61%). This demonstrated that CIN smears are more likely to include metaplastic cells compared to negative smears and the two types of smear do not differ significantly with regard to columnar cells.

CONCLUSIONS

In order to make a cytological diagnosis of CIN, attention must predominantly be focused on the metaplastic component of endocervical cells.